"Move not, unless you see an advantage; use not your troops unless there is something to be gained; fight not unless the position is critical."
"No ruler should put troops into the field merely to gratify his own spleen; no general should fight a battle merely out of pique." (Sun Tzu, 'The Art of War', XII, 17 & 18)
Having run out of good options, President Obama has chosen one of the bad ones, perhaps the worst. He is being seen as pusillanimous and weak. He has become the butt of satires in "The New Yorker" and "The New York Times". One of the worst situations for any political leader is to become a laughing stock. Even worse, when you are president of the United States, is the danger that the country will also become a laughing stock.
When members of Congress of his own party began to join the Republicans in demanding that he should not take military action in Syria without the authorization of Congress, he reversed his previous position that he could do it on his own authority, and simultaneously signaled that he didn't consider the matter very important after all when he did not call Congress immediately back into session, but said he would wait until the end of their normal annual recess on September 9th to hold the vote.